Studies at the basic and clinical level continue in several heritable bone disorders. In addition, a novel family of vertebrate anti- microbial peptides isolated from Xenopus skin were characterized. Extensive study of the molecular lesions at the relationship between the defect at the protein level and the clinical phenotype. A novel method was developed for mapping point mutations in mRNA species, utilizing RNA-RNA mismatch. Clinical studies on the basis of growth failure in patients with O.I. have identified deranged expression of growth hormone in several individuals with classical O.I. and hormonal intervention has been initiated. Cloning of the human and bovine bone-specific alkaline phosphatase cDNA has continued. A novel family of anti- microbial peptides were isolated from Xenopus skin and a corresponding cDNA was cloned.